If you have not already done so, please read Blog Posts 1 through 5 that describe how sleep is important and beneficial. I will post specific information for parents and children based on my book, “Healthy Sleep Habits, Happy Child.” Please do not be put off by my book’s length. This is a reference book. Read only the topic of interest to you.
How Adults Feel
The Stanford Sleepiness Scale describes seven levels of daytime alertness and sleepiness:
| Level | Description |
| 1 | Feeling active and vital; alert; wide awake — optimal alertness |
| 2 | Functioning at a high level, but not at peak; still able to concentrate |
| 3 | Relaxed; awake; not at full alertness; responsive |
| 4 | A little foggy; not at peak; let down |
| 5 | Fogginess; beginning to lose interest in remaining awake; slowed down |
| 6 | Sleepiness; preferring to be lying down; fighting sleep; woozy |
| 7 | Almost in reverie; sleep onset soon; lost struggle to remain awake |
Daytime sleepiness from disturbed sleep typically begins as a mild itching or burning in the eyes. Eyelids feel heavy. As sleepiness deepens, long eyeblinks and heavy eyelids reflect the brain’s attempt to shift into sleep mode. Limbs feel heavy. Motivation decreases. Concentration falters. Speech slows. Yawning and eye-rubbing appear. As the state deepens further, the eyes begin to close and the head begins to nod.
How Adults Appear
Observers can read drowsiness in another person’s behavior before that person may be fully aware of it themselves:
Not drowsy — optimal alertness: fast and frequent saccadic eye movements; frequent body movements; eyeblinks with fast eyelid closure; active engagement with the environment.
Slightly drowsy: slowing saccadic eye movements; lips parting; infrequent eye movements and staring; eyelids beginning to droop.
Moderately drowsy: frequent slow blinks; mouth movements; postural restlessness and fidgeting; touching the face; eyelids drooping to less than half the pupil; yawning; a tired complexion.
Very drowsy: voluntary effortful blinking; frequent yawning and deep breathing; unnecessary movements such as head bobbing and shoulder shifting; slow blinking and slow eye movements; blank staring at a fixed point; inability to focus; eyelids drooping to more than half the pupil.
Extremely drowsy: closed eyes; head tilting forward or backward.
This progression is observable. The signs are visible before the person experiencing them may notice — which is precisely why external observation matters for children, who cannot reliably report their own internal state.
Practical Points
Acute sleep loss is inevitable. A missed nap, a bedtime that arrives too late — this is real life. The mood, behavior, and performance changes that follow are real but reversible. A reset to pay back the sleep debt restores the child to baseline. When disruptions are infrequent, recovery is complete and no lasting harm occurs.
Chronic sleep loss is a different matter. Animal studies and research in children strongly suggest that chronic sleep deficits impair brain development. We do not yet know precisely what kinds of disruption, in what amounts, over what duration, constitute a lasting threat to the developing brain. But the possibility of permanent harm is real.
Advice
Illnesses and unavoidable circumstances will occasionally disrupt sleep. Try to avoid optional social circumstances that push your child into cumulative sleepiness. Plan for recovery when sleep loss occurs.
Respect your child’s need for sleep by watching for drowsy signs. Avoid pre-sleep arousal and cumulative sleep loss. To promote self-soothing skills, give your child less attention when the brain needs to sleep — for naps and at night. And most importantly, enjoy your child’s company when she is awake.
The drowsy signs described above in adults have their parallels in infants and children. Learning to read them — in your child, before the moment has passed — is one of the most practical skills this blog exists to teach.
Watch your child, not the clock.
— Marc Weissbluth, M.D.
